We present a new method of scaling hydrodynamic data obtained from a 2D gas-solid fluidized bed, establishing links between 2D and 3D geometries. The methodology proposed may also be useful for verifying 3D-3D dynamic scaling. According to the chaos scale-up methodology proposed by Van den Bleek and Schouten, the information balance is taken into account. The complexity shown by these systems is measured as the Kolmogorov entropy. Fluidized beds of different geometry (2D, 3D) performing under the bubbling regime were operated at different bed height and bed aspect ratios by fluidizing several particle groups belonging to Geldart groups B and D. Finally, an empirical correlation is proposed to compare fluidized bed hydrodynamics. This correlation relates the global information flow of the system K-G = K F-r, to the relative Reynolds particle number. (c) 2005 Elsevier Ltd. All rights reserved.